The present invention relates generally to the controlling and positioning of vehicles, and more particularly to the controlling and positioning of vehicles based on relative positioning of a master vehicle.
Determining the position of an individual or vehicle is well known in the art. Global Positioning Satellites (GPS) systems, Carrier Phase Differential GPS (CDGPS) and other positioning systems provide accurate positioning for a car, a truck, an agricultural vehicle, an aircraft and other types of vehicles. Control systems have been developed to accurately determine the location of a vehicle and to aid in providing directional control for that vehicle based on the determined location (see for example, U.S. Pat. No. 6,052,647, Parkinson et al.). However, this control system is limited to the control of a single vehicle. Further, this system requires the vehicle to be given a predefined path to follow. This predefined path requires the operator to determine the size of the area the vehicle is suppose to travel upon, determine what needs to be performed, and precisely determine how to implement and control the vehicle prior to activating the vehicle. This is time consuming and requires detailed measurements prior to activation. Further, it limits the implementation of performing the desired task to the specific predefined path and is susceptible to errors in entering the path as well as following a path based on potentially inaccurate measurements.
Another vehicle control system for agricultural vehicles provides for a master vehicle to determine the location of itself as well as a slave vehicle and to provide control for the slave (see U.S. Pat. No. 6,148,255, van der Lely). The slave vehicle is controlled by a control system from the master vehicle, where the control is being provided radiographically or by cable. The slave vehicle further requires video cameras arranged to allow the controller of the master vehicle to view both the forward and the rear views from the slave vehicles. The operation of this system requires visibility and thus limits implementation.
Further, the control limits the operation the slave vehicle to a position directly behind and in line with the master vehicle, or directly adjacent to and parallel with the master vehicle. The master vehicle can only control the slave vehicle along a single pass across a field. The master vehicle is unable to control the slave vehicle in turns or re-align the slave vehicle on a new path or pass. The turning and re-aligning must be performed manually. Still further, the control of the slave vehicle is performed by the master vehicle. Therefore, the master vehicle is burdened with the control and as such, the number of slave vehicles to be operated is severely limited due to the amount of computational requirements placed on the master vehicle in attempting to control the slave vehicles.
The present invention provides for a method and apparatus for providing navigation and positioning for at least one or more slave vehicles, wherein the slave vehicles provide their own navigation based on a location of a master vehicle. In one embodiment, the present invention is implemented through a computer readable medium operating on one or more processors. The method and apparatus allow a slave vehicle to receive a location of a master vehicle and a location of the slave vehicle. Once the location of the vehicles are known, the slave vehicle determines a desired position for the slave vehicle based on the master vehicle location. The slave vehicle determines if adjustments are needed to position the first slave vehicle at the desired position and implements the adjustments if adjustments are needed. The slave vehicle is further capable of operating in one of a plurality of modes and further is capable of transitioning from one mode of operation to a second mode of operation in optimizing navigation and control.
In one embodiment, the slave vehicle determines the desired position by determining a first destination point relative to the location of the master vehicle. The slave vehicle is then capable of determining a first optimal course needed to position the first slave vehicle at the first destination point and to determine the adjustments to implement the first optimal course. In one embodiment, the slave vehicle determines a pseudo destination point based on the location of the master vehicle, and while determining the optimal course, the slave vehicle utilizes the first pseudo destination point in determining at least lateral adjustments. The navigational method and apparatus is further configured to allow the slave vehicle to determine the optimal course taking into account boundaries and obstacles.
In one embodiment, the slave vehicle determines the desired position by determining a first fixed point relative to the master vehicle location, and determines if adjustments are needed including determining if the first slave vehicle is located at the first fixed point. The slave vehicle determines the fixed point based on fixed point offset coordinates which are utilized in cooperation with the location of the master vehicle. In positioning itself, the slave vehicle determines a trajectory of the master vehicle, and a trajectory of the slave vehicle. The slave vehicle is then capable of determining if adjustments are needed including determining if the trajectory of the first slave vehicle is parallel with the trajectory of the master vehicle. In one embodiment, the trajectory is determined based in part on a heading of the slave vehicle.
In one embodiment, the slave vehicle provides navigation by receiving at least a first portion of a master vehicle path, and generating at least a first portion of a slave vehicle path based on the at least the first portion of the master vehicle path. Once at least a portion of the slave path is generated the slave vehicle determines if adjustments are needed in maintaining the slave vehicle on the slave vehicle path, and implements the adjustments if adjustments are needed. In generating at least the first portion of the first slave vehicle path, the slave vehicle generates at least the first portion of the first slave vehicle path by offsetting at least the first portion of the master vehicle path by an offset. In determining if adjustments are needed, the slave vehicle compares the location of the first slave vehicle with the first slave vehicle path, and determines if the first slave vehicle is off of the first slave vehicle path. If the slave vehicle is off the slave vehicle path the slave vehicle determines a trajectory to return the first slave vehicle to the first slave vehicle path. In one embodiment, the slave vehicle determines what steering adjustments are needed to make turns to follow the first slave path, and calculates the distance between the location of the first slave vehicle and approaching adjustments to a current trajectory of the first slave vehicle to continue on the first slave vehicle path.
As introduced above, the present method and apparatus is capable of providing navigation and control for a plurality of slave vehicles. Each slave vehicle provides its own navigation and control. Each slave vehicle utilizes the master vehicle location in determining its desired location. In one embodiment, the master vehicle can be defined as different vehicles for different slave vehicles. Such as, defining a first slave vehicle as the master vehicle for a second slave vehicle.
In one embodiment, the novel apparatus for providing vehicle navigation includes a communication controller configured to at least receive location information for at least a master vehicle and a slave vehicle, a location generator coupled with the communication controller, and configured to determine locations of at least the master vehicle relative to the position of the slave vehicle, and a desired location controller coupled with the location generator, and configured to determine a desired location of the slave vehicle relative to the location information of both the master vehicle and the slave vehicle. In one embodiment, the desired location controller is a trajectory controller configured control the trajectory of the slave vehicle, where the desired location controller includes a destination point calculator configured to determine a desired destination point relative to the master vehicle, and a course calculator coupled with the destination point calculator, and configured to determine an optimal course such that the slave vehicle acquires the desired destination point. In one embodiment, the desired location controller is a path controller configured to generate at least a slave vehicle path such that the slave vehicle follows the slave path.